The present disclosure relates to a force transmission device, in particular a rocker lever or finger-type rocker, for producing an operative connection between a camshaft and a gas exchange valve.
It is generally known to use variable valve drives for changing switching times and valve strokes of gas exchange valves of an internal combustion engine during the operation of the internal combustion engine. A plurality of variable valve drives are known in the prior art.
DE 10 2011 052 246 A1 discloses an integrated variable-valve actuator device of a variable valve stroke device. The device has a rocker lever which rotates on a rocker lever shaft and which has an oil supply line which selectively supplies oil. The device has a fastening device which passes through a side of the rocker lever, and oil which is supplied by the oil supply line is discharged through an oil passage. The device has a valve bridge which is arranged at the bottom of the fastening device and places valves under pressure. The device has an actuator device with an actuator piston which is inserted into the valve bridge and is designed with an oil supply passage. The device has an actuator spring which is inserted into the actuator piston and which acts upon the actuator piston with an elastic force. The device has a variable control device which is arranged at the bottom of the actuator piston and which sets the heights of the actuator piston by a movement which is produced by the hydraulic pressure of the oil which is supplied by the oil supply passage.
DE 10 2005 040 649 A1 discloses a variable valve drive of a cam-actuated gas exchange valve of an internal combustion engine, having a force transmission device which is arranged between the cam and the gas exchange valve and which comprises a hydraulic lifting device having a pressure piston which is longitudinally displaceable in a cylinder, which piston delimits a pressure space connected to a pressure medium supply of the internal combustion engine and which, when acted upon by high pressure, allows an actuation of the gas exchange valve that is independent of the cam. Here, the force transmission device is intended to be designed as a swing or rocker lever mounted rotatably on a lever axle, wherein the lever axle has a pressure medium-channelling longitudinal duct as a connecting path between the pressure medium supply and the pressure space.
U.S. Pat. No. 6,422,186 B1 discloses a system for actuating a valve of an internal combustion engine. The system has a rocker lever with a piston depression. A lost motion piston is displaceably guided in the piston depression.
Further valve drives are known for example from EP 1 087 109 A2, DE 199 15 531 A1 and EP 0 255 668 A2.